Bank stocks suffered the worst single-day performance since the tariff-driven chaos of April, according to Wall Street analyst Chris Marinac. The KBW Bank Index fell nearly 6% intraday, falling to its lowest level since March 2025. The collapse of a UK mortgage lender, Market Financial Solutions (MFS), left several major Wall Street firms holding on billions of dollars in worthless loans. The company had been under the influence of artificial intelligence, which could potentially eliminate half of its workforce. The fear of this disruption led to a sharp selloff for bank investors, with JPMorgan Chase (JPM), the most cushioned of the group, closing at 3.5%. The Dow Jones Industrial Average dropped 521 points or 105 points, while the S&P declined 0.43% and Nasdaq lost 092%.